text:
Where does the flat plate theory in this paper come from?
The aerodynamic model cited in this paper (pdf) as "flat plate theory" was a good first-order approximation of the aerodynamics of a perching glider. I immediately saw the similarity with the Newtonian theory that works well in hypersonics, but it is only a similarity, not the same.
Around the internet I found these other two articles: (1) and (2), which make reference to this flat plate theory in the context of wind turbines.
My questions are:

Where does this flat plate theory come from?
In what textbook or article or other bibliographic reference can I find its derivation?

Edit:
Here is another article that cites this flat plate theory, now in the context of aircraft flight dynamics. This one makes reference to (1).
Here is yet another one in the context of wind turbines.

Ludwig Prandtl's lifting line theory produces a Taylor series as the result of the lift equation, and in almost all books this has been simplified just to the first term of the series, which then was even robbed of its sinus function to simplify it even further by using a small-angle approximation.
What you will find in books today is something like: $$c_L = c_{L\alpha}\cdot\alpha$$
$c_l$ is the lift coefficient, $c_{L\alpha}$ is the lift curve slope and $\alpha$ is the angle of attack in radians.
What the author should at least mention (but I think most are ignorant of this detail) is that a more precise version would be: $$c_L = c_{L\alpha}\cdot\sin\alpha$$
And now the books should tell you that there are more members in the solution to the lift equation; the one above is only the first one which dominates the result for small values of $\alpha$. But they don't. That is OK when the aircraft moves only through the small angle of attack region of attached flow, but for the perching motion you need to look at bigger angles, so the small-angle solution will produce noticeable errors.
The lifting-line theory assumes inviscid flow and does not know about flow separation. Perched flight of birds would be impossible without the high angle of attacks which produce flow separation and makes use of instationary effects which delay separation. All this is not covered by lifting line theory, but nevertheless it produces quite useable results. I guess, however, that the equation in the paper was found empirically.
The lift equation cited in the paper is a consequence of observing forces in a 360° polar, one where the airfoil is rotated through full 360° instead of the narrow range between maybe -8° and +12° where flow is attached and lift forces vary linearly with the angle of attack.
The plot below is from Hoerner's book "Fluid Dynamic Lift" (Scribd) and shows the results of several measurements over 180°. Apart from the spikes around 15° and 175°, the forces correspond well with $c_L = x\cdot\sin\alpha\cdot\cos\alpha$, where $c_L$ is the lift coefficient, $\alpha$ denotes the angle of attack and $x$ is a proportionality factor (the paper postulates $x$ = 2).
$c_L$ over 180° angle of attack from Hörner's book">
A flat plate has no leading edge radius and, consequently, no leading edge suction, which would be responsible for the aforementioned spikes. Therefore, the simple trigonometric approximation will fit the data quite well.
Both the flat plate and Newtonian theories assume the aerodynamic force to be orthogonal to the plane of the wing or plate, and when you take the portion of that force which is orthogonal to the direction of movement, which is how lift is defined, you get above trigonometric equation. This is simple geometry and shows no deeper insight into fluid mechanics.

Great answer, but I have some questions, you say the formula calculates the portion of the wing that is orthogonal to the direction of movement, but to to the value of $c_l$ would then be a simple sine function. Where does the cosine come from?

The link you added does not contain the book in pdf directly but a download button instead, and the file to download is an executable.  Is that safe?

In other words: The coefficient of pressure is Cp=xsin(AoA). The lift, by definition, is obtained when you project this into the direction perpendicular to the flow: Cl=xsin(AoA)cos(AoA).  However, the question is: where that Cp comes from.  Peter Kämpf recognizes this fits the data, but that is not the answer I am looking for (I already have that answer from a lot of papers).  I'm looking for a theory that explains why Cp=xsin(AoA) fits the data, in the same way there is an explanation why the Newtonian theory holds in hypersonic flow. A simple data fit is not normally called "theory".

@KeyDamo: Sorry, I didn't check this. Thanks for letting me know; I replaced the link with one pointing to Amazon. And you are right about the theory. I will edit the post when I have more time.

@KeyDamo: Now I have added a theory section, but I think that the equation in the paper is based on empiricism.


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What are the weather minimums in order to take off under IFR conditions?
I've heard different answers for what limits if you can take off IFR from an airfield. I've heard that you have to be restricted to the lowest compatible mins on an instrument approach field and I've heard that you can take off if the ceilings are 0' and visibility is 0.
Does anyone know the answer or where I could find the answer to this question? Does this change for the military?

Carlos answer is absolutely correct but there is some more elaboration on what those minimums are if you are not legal to operate 0-0
Under FAR 91.175 you will find the departure minimum regulations

(f) Civil airport takeoff minimums. This paragraph applies to persons
operating an aircraft under part 121, 125, 129, or 135 of this
chapter.

Unless otherwise authorized by the FAA, no pilot may takeoff from
a civil airport under IFR unless the weather conditions at time of
takeoff are at or above the weather minimums for IFR takeoff
prescribed for that airport under part 97 of this chapter.

If takeoff weather minimums are not prescribed under part 97 of
this chapter for a particular airport, the following weather minimums
apply to takeoffs under IFR:
(i) For aircraft, other than helicopters, having two engines or less -
1 statute mile visibility.
(ii) For aircraft having more than two engines - 1/2 statute mile
visibility.
(iii) For helicopters - 1/2 statute mile visibility.

Except as provided in paragraph (f)(4) of this section, no pilot
may takeoff under IFR from a civil airport having published obstacle
departure procedures (ODPs) under part 97 of this chapter for the
takeoff runway to be used, unless the pilot uses such ODPs or an
alternative procedure or route assigned by air traffic control.

Notwithstanding the requirements of paragraph (f)(3) of this
section, no pilot may takeoff from an airport under IFR unless:
(i) For part 121 and part 135 operators, the pilot uses a takeoff
obstacle clearance or avoidance procedure that ensures compliance with
the applicable airplane performance operating limitations requirements
under part 121, subpart I or part 135, subpart I for takeoff at that
airport; or
(ii) For part 129 operators, the pilot uses a takeoff obstacle
clearance or avoidance procedure that ensures compliance with the
airplane performance operating limitations prescribed by the State of
the operator for takeoff at that airport.

If no take off minimums are specified you can use the "standard
minimums" which are listed here

Unless operating specifications state otherwise, the following
engine-based minimums apply for aircraft operating under FAR parts
121, 125, 129, and 135:
One or two engines: one statute mile of visibility; no ceiling minimum
Three or more engines: one-half statute mile of visibility; no ceiling
minimum
Helicopters: one-half statute mile of visibility; no ceiling
minimum

Takeoff Minimums (and Departure Procedures) are also published by geographic area so you can look them up for any non standard airport. For example KDXR is stuck in a valley and has some non standard departure minimums.

As Carlo also notes, while you can take off in 0-0 its generally a risky proposition at best, here are some considerations as to why I effectively never do it:

If something goes wrong but Im still capable of flight, I cant get back to the runway as there are no practical 0-0 landing procedures for the aircraft I fly
If something goes wrong and and Im not capable of flight I have no practical means of picking an emergency landing spot as I will presumably be in IMC immediately
Obscured low terrain while always a concern becomes an even larger issue
There are a lot of accelerative forces and pitch changes going on between the start of your takeoff roll and the tower handing you off to departure, this means there are lots of forces acting in lots of directions to disorient you, more so than say a VMC to IMC transition in level flight on a smooth day.
Low level clouds, fog, and IMC often brings with it other weather concerns, I don't really want to be worrying about picking up icing at 100' AGL?

Note that OpSpecs generally give air carriers much lower takeoff mins than the standard one (or 1/2 for 3+ engines) mile. Given the necessary lighting & equipment, i.e. High Intensity Runway Lights, centerline markings (day) or centerline lights (night), mins in the ballpark of 500' RVR are possible. When doing that, a takeoff alternate would be necessary, since you generally couldn't return to land with visibility that low.

This is dependent upon the type of flight operation that is being conducted as well as the circumstances. In the USA, commercial flight operations under Part 91, 119, 121 and 135 do not permit departures in zero-zero conditions.  However recreational flights under Part 91 in an appropriately equipped aircraft and with a properly certificated pilot do allow for zero-zero departures.  While there is no legal restriction placed upon upon such a departure, the PIC should carefully perform a risk management analysis of such a proposed departure as there is little room for error or pilot task saturation in the event of an emergency.  This kind of IMC should be an immediate red flag to cancel of reschedule a general aviation flight for better WX, or seek another mode of transit.  Impulsively making those kinds of departures has killed people in the past, similar this deadly accident, which happened in Bartow, FL on December 24, 2017, killing 5 people.  The tragedy was, if the pilot had waited a mere two more hours the fog would have lifted and he could have departed in VMC.  Another case were very low instrument conditions combined with pilot hazardous attitudes killed people for no good reason.

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On the Ka-50 coaxial helicopter, why does the bottom rotor flap up on the right side instead of in front during forward flight?
In the game DCS World, when flying the Kamov Ka-50 Black Shark flying forward at high speeds, the bottom rotor will flap up on the right side of the helicopter (also note that the top rotor is flapping up on the left, though not as much):

However, according to the following diagram:

While the maximum up-flap velocity is on the right side, the actual max up-flap displacement is in front of the aircraft. Thus, shouldn't the bottom rotor be flapping up in front of the helicopter, instead of on the right? This effect only occurs at high speeds, at lower speeds it's either not there or barely perceptible:

Is this up-flap behavior correct, and if so, what is causing it?

I was literally posting the same question just now - this somehow didn't come up in the search. But yeah, same logic in the question, which unfortunately I lack the answer for.

As far as my understanding goes, the rotors should never flap differently from each other, and should not flap at all at steady flight.

This is does appears to be partially correct behavior for a Ka-50 in forward flight (in the low speed example)--but not because of gyroscopic procession.  It also may be plagued with transient artifacts from the DCS flight mechanics model.
According to DCS, the Ka-50 rotor is modeling using blade-element momentum theory with some inflow model, so the basics of its aerodynamics should be correct.  That said, this shouldn't account for blade/vortex/body interactions or other higher order effects.  Based on the same source, DCS implies that they use a rigid-blade model (that is, a rigid blade rotating on flap/lag hinges) for their rotor blades, which allows them to model blade motion and couple their aerodynamic model with some rotor dynamics.  This is impressive for a sim to have, but remember that they are missing significant interactions between rotors, let alone the body.  They can reproduce the performance from certain phenomena in flight, but they don't go into detail of what else goes into their model, so I cannot comment any further.  However, I can say the following.
Gyroscopic precession does exist, this is true, but it is a much simplified explanation of why helicopter rotor blades exhibit a phase lag that delays a blade's physical response to an applied load.  Rotor blades are not gyroscopes, and, in fact, the phase lag for rotor blades is not always 90$^\circ$ but varies depending on the design of the rotor system.  As for why the FAA and other pilot-oriented groups continue to teach that gyroscopic precession is the reason why it occurs: I have no authoritative answer, but, as with how the FAA incorrectly teaches about lift, teaching the "actual" reason why an aircraft does what it does will not necessarily teach you how to fly the aircraft better (unless you have an extremely well-developed understanding of fluid mechanics).  Getting the explanation "good enough" (so that you have a useful hermeneutic for how the vehicle interacts with the air is sufficient to enable you to use the aircraft safely) seems to be the mantra--which makes some sense.  Else, no one* would be allowed to fly!
Regardless, to the point.  Let's talk about phase lag, how to control a helicopter using a rotor, and how those two come together.
Phase Lag and Helicopter Controls
Phase lag refers to the difference in when a force is applied to a dynamic system in resonance and when its physical effect manifests itself.  This gets a little complicated in a helicopter's rotor system since, in order to control the vehicle, the rotor itself has to be tilted in the desired direction of motion.  Keep in mind that the rotor (I speak in the singular, but I'll apply this to the Ka-50 in a minute) is the primary source of propulsion for the helicopter, so, to move anywhere, the rotor has to be pointed in the direction of motion, as illustrated below.  The purple line is the plane connecting the tips of the rotor blades (or the tip path plane) during hovering flight, and the orange line is the tip path plane in forward flight.

You can also see this in this video of a hovering UH-60 Blackhawk (note the level tip path plane) as compared to this video of a Blackhawk in forward flight (note the tip path plane tilted in the direction of motion--more evident during the first half of the video).  A caveat, though: the rotor on the Blackhawk is actually set at a small angle forward to decrease parasitic drag and decrease the body pitch angle in forward flight.  This is particularly evident in the first video, wherein the helicopter is actually pitched upward when the rotor tip path plane is horizontal.  I'm using the UH-60 as an example, but this is a fairly common practice.
In short, you have a single force vector, and you have to point that force vector in the direction you want to push the helicopter.
DISCLAIMER: if you don't want to learn about phase lag and just want the answer, skip to the last section now.  A digression on phase lag is ahead.
Hence, whether the rotor is articulated or some form of rigid, it is designed such that the blades can flap as needed.  The Ka-50 rotor does have flapping hinges, as you can see in the image below from how the blade is slightly angled relative to the blade grip extending from the rotor hub.

So where does this leave us?  I'll explain phase lag in a minute, but the confluence of phase lag and blade flapping is important to grasp first.  For instance, if I put in a control input to a rotor to make the vehicle move to the left, I would expect the rotor disc to tilt to the left by way of the blades flapping up on the right side of the helicopter and down on the left side.  However, since the physical response and the aerodynamic loads are out of phase, I have to put in the control input prior to when I want the effect to manifest.  If this effect was gyroscopic, I would have to pitch the blades as they passed over my tail or nose (90$^\circ$ prior to the flapping effects I want to see).  However, if we look at a Robinson R-22, it ends up being more like 72$^\circ$ prior instead of 90$^\circ$.  And it's not the only one (though typical values for articulated rotors do end up being closer to 90$^\circ$, if memory serves)!  However, this is because the effect is not due to gyroscopic precession, but is a result of rotor design.
A flapping rotor system is the product of the a variety of forces, including mechanical damping (think of a dashpot, although that particular item is not necessarily the case), stiffness (think of a spring), aerodynamic damping (resistance to motion proportional due to changing aerodynamic forces), aerodynamic forcing (think lift, or what's causing the flapping in the first place), centrifugal or inertial forces (what's trying to keep the blade level), and "coriolis" forces, to name a few.  These interact with a rotor blade that is hinged with some amount of offset from the center of rotor as well, which we can see on the picture of the Ka-50 rotor hub, which also changes how the blade responds to aerodynamic forces.  As a result, we can tune the rotor system we design to respond in a particular way to aerodynamic forcing.  However, it changes the phase lag of the system.
Visualizing the Effect
One way to visualize this (if you like math -- if not, I'll provide a physical example too) is using an Argand diagram, which can be used to show components of a spring/mass/damper system (a rotor system is an example).  This would come from the Fourier transform of an equation having the following form, where $I$ is inertia, $b$ is the damping coefficient (higher the coefficient's magnitude, the more resistance to motion there is), $k$ is the stiffness of the flapping hinge (the "restorative" force in the diagram), $\beta$ is the flapping angle, $\dot{\beta}$ is the flapping velocity, and $\ddot{\beta}$ is the flapping acceleration.  $F(\Psi)$ is the aerodynamic forces that create the blade flapping motion.
$I\ddot{\beta}+b\dot{\beta}+k\beta=F(\Psi)$
For example, the diagram below shows a system where the spring (rotor system: the restoring force which is dependent on actual flap angle) is dominant, making the system's physical response pace closely with the input force.  Conceptually, that makes sense -- if I have a stiff spring, the amount of force I use to compress the spring will match very closely with the spring's compression (in the absence of a damper or much inertia).  I can get that from the Argand diagram from doing vector addition with the 3 components I have plotted.  If I did so, the resultant vector would lie very close to the "restorative" axis, or to the right side of the horizontal axis.

However, what if the damping is much larger and closer in magnitude to the restorative vector?  This more usual for a helicopter with articulated rotor blades.  If so, we get an Argand diagram that looks more like this:

If I do my vector addition here, I see that the resultant vector, and thus the physical manifestation of my input force, is $90^\circ$ out of phase with my input.  A physical analogy would be if I connected a spring to a pneumatic cylinder and then tried to, alternately, compress and extend it.  The amount of force I apply is no longer directly proportional to the compression or extension of the spring, but is out of phase with the spring's physical motion due to the presence of the damper.  If I had a spring with a lot of mass, you could see how that would further complicate the problem.
Putting it all together: what does this mean for the Ka-50?
Right: so, in the pictures provided (copied below), you show the Ka-50 rotor flapping by small amounts during lower speed forward flight (quoted IAS was 60 kph).

Note that both rotor discs are flapping up as they pass over the tail.  As said, in order to maintain speed, the Ka-50's rotors need to be tilted in the direction of motion, though this should only be a transient feature as the vehicle pitches into the direction of motion.  If they were not, parasitic drag (and other sources) would slow the vehicle down.  To maintain speed, a force has to be continually applied in the direction of motion.  Hence, the aerodynamic forces are applied earlier in the rotation to induce both rotors to flap up as the pass over the tail of the aircraft.  The 60 kph case is also useful because flapping due to advancing/retreating blade effects are relatively small as compared to the second case, shown below.

In this case, the rotors are obviously tilted left and right, respectively: which is strange.  Judging from the horizon lines in both pictures, it would appear that the helicopter is pitched down more in this higher speed case as well, which makes sense, since the blade flapping angle over the tail seems to be relatively small.  The vehicle also seems to be in a shallow right bank.
As a result, and I'll be perfectly honest, I'm not entirely sure why the rotors are tilted in opposite directions, and this is where I doubt the veracity of their model.  Due to the high speed, which should be leading to some interesting aerodynamics, I'm placing a bet on their modeling starting to break down.  If they are using an inflow model that approximates wake motion, some of the assumptions of that model may be breaking down at this high of an advance ratio, leading to unexpected blade motion.  An Jan Hudec says in the comments, both rotor planes should be parallel to each other.
*If I may perpetuate the legend: no one, that is, except Peter Kämpf.

Rather than saying rotors are not gyroscopes I would say they are more complex case than for what the simple 90° gyroscopic precession is derived. When you start deriving the gyroscopic effect by observing a point on the gyroscope, you do the same thing as for the rotor blade, but then you make two assumptions: that the force is small compared to the rate of rotation, and that the axis does not resist the precession, neither being true of helicopters. If you consider a gyroscope that is only starting to spin, the phase lag will change from 0° to 90° continuously.

The flapping in any steady state, whether hover, forward flight, sideways flight etc. only depends on the centre of gravity. For forward flight, the rotor and body pitch forward together, the rotor just leads a bit with flapping as the active element, and the body lags due to inertia. But it must end in the same relative position as for hover, because the lift is still perpendicular to the rotor plane of rotation and acting through the hub, and the centre of gravity must be in its action line, otherwise there would be pitching moment (ok, centre of drag shifts it a bit).

Most helicopters just mount the rotor tilted forward relative to the body to make the forward pitch less pronounced in forward flight, at the cost of noticeable backward pitch in hover.

That's good point about gyroscopic procession being a simplified version of the explanation: I've updated to mention that.  However, I disagree about the flapping angles in steady state always being the same, regardless of airspeed.  For a given shaft tilt angle, the cyclic flapping angles will change with airspeed, as will the cyclic control angles, in order to keep the aircraft in trim at that speed.  This is in response to asymmetric changes in lift production around the rotor in forward flight, an effect that DCS's aero model (which includes an inflow model) should be able to capture.

However, I would definitely agree that I have some doubts about the images being of a vehicle in steady state flight.  I think there's a good chance that the latter image captures some transients, which is throwing things off for me.

In forward flight, the cyclic is angled forward while the asymmetry due to airspeed tries to tilt the rotor aft, and the effects should cancel. The reason is that tilting the rotor relative to the shaft is what creates a pitching moment, but in steady state the pitching moment has to be zero. Unless the centre of drag coincides with centre of gravity, drag also creates some moment, so the flapping angle does change with speed as it has to compensate for that, but if the centre of gravity is above centre of pressure, the flapping angle might even be aft relative to hover.

The image captures may be of some transient state, but even then the rotors should always flap the same way. There might be slight difference as the controls can't be rigged to compensate all the effects precisely, but it will be very small.

The rotor system in flight is very complex all parts affecting everything else, the basic answer would be the blades must move up an down to balance the forces on the rotor system to prevent to much lift on the advancing side, which would roll the helicopter to the retreating side [they also move forwards and back to bance the flapping motion for physics reasons, you can look up Lead lag hinges]
The reason they flap more at higher speeds, is due to "dissymmetry of lift" as the aircraft speeds up, the lift difference between the advancing blade, and retreating blade is more pronounced, requiring more flapping to equalize it.
I do see your confusion, but the behavior is correct even if it seems strange.
Good explanation:
https://www.thehelicopterstudyguide.com/what-is-flapping/
A video of flapping:

I understand what flapping is, but I don't understand why it occurs on the right side instead of in front. Based on the 2nd image I linked, the right side is just the max up-flap velocity; the front is the actual max up-flap displacement. This makes sense because the blade is advancing into the wind on the entire right side, so the upward movement slows down, but it's still moving upwards. Every resource I've found online simply says "because dissymmetry of lift" and leaves it at that, but I want to understand why it causes this and why it conflicts with the info in the 2nd image.

The physics is beyond me, but some possible factors include the force pulling the blades strait out [and therefore down] is vary powerful, also remember that the rotor "plane" of most helicopters is offset both forwards and sideways for a better cruse attitude [mast is tilted], which may affect  how it looks. hope someone else can expand.

The flapping diagram shows the theoretical case where the flapping would place the blade tip track if the swash plate was set at "neutral" so to speak.  Since that tip track is not desirable for forward flight, the swash plate is angled "automatically" by cyclic input to put the resulting disc plane where it needs to be for forward level flight.

Is this up-flap behavior correct, and if so, what is causing it?

Yes it is correct. The rotors turn in opposite directions, to compensate each other for their induced torque - the whole point of using two rotors, eliminating the need for a tail rotor.
The advancing blade flaps up, the retreating blade flaps down.

TL;DR, it's just a game and is not really realistic.
Flapping isn't there to allow the rotor to compensate for increased lift on the advancing blade, it is there to make the helicopter controllable.
The helicopter cyclic control adjusts the blade pitch depending on the position of the blade along the cycle using a swashplate. When the pilot pushes the cyclic forward to transition from hover to forward flight, the swashplate tilts so that the pitch on the retreating side increases, making the blade flap up and reach highest position aft, and decreases on the advancing side, making the blade flap down and reach lowest position forward. The swash plate itself is tilted forward and the scissor links that connect the blade to it take care of the necessary lead; the end effect is that the rotor tries to keep itself aligned with the swash plate.
The lift always acts perpendicular to the plane of rotation and through the hub, so as the rotor tilts (by flapping), the action line of lift tilts with it, gets behind the centre of gravity, and the whole craft pitches forward.
Now only as the helicopter picks up speed, the increased relative speed will make the advancing blade produce more lift (though the flow will be slightly from above due to the tilt, reducing the effect) and the retreating one will produce less lift. And you are correct that this will lead to the rotor flapping up forward and down aft.
But this flapping will just add to the flapping caused by the swash plate. The rotor will now rotate tilted aft compared to the swash plate. If the pilot centred the cyclic, the rotor would pitch up, the craft would follow and slow down (and climb unless the pilot also lowers collective).
But as long as the pilot keeps the cyclic pushed forward to maintain the forward
speed, the rotor will rotate roughly perpendicular to the shaft, the slight offset depending on position of centre of gravity and centre of drag. And the advancing and retreating blades will be producing the same lift, the higher air speed on advancing side compensated by lower angle of attack commanded by the forward tilted swashplate.
Last, for a coaxial twin-rotor helicopter like the Ka-50, the rotors will always be co-planar in any manoeuvre. I've said that the lift always acts perpendicular to the disk, so whenever the rotors were not co-planar, they would be trying to pull the shaft in different directions, creating no other effect than bending force on the shaft. So the control system is designed to induce the same tilt in both rotors.

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How do you choose CAT II vs. CATIII ILS?
When should we use CAT II or III during landing in bad weather? What we have in our country the standard shows 800m and RVR of 550 m for the ILS, which category procedure should be used if the visibility below or above?
On the other hand nothing tells us if it is CAT II or CAT III inside the charts except at the large airports.
And regarding the DH during the CAT III is it always 50 RA ?

If both are available for the runway you're using, it's often easiest just to set up the Cat III, because you have the least risk that way of a random cloud between the Cat II DA and the Cat III DA interfering with your approach.
That said, there may be reasons to prefer the slightly higher mins of the Cat II, and those are typically specific to your equipment and your procedures.  Perhaps crosswinds, either steady or gusts, make the Cat II more desirable, or if your equipment has a limitation on "XYZ must be operative for Cat III approaches" and that happens to be deferred on MEL for you, then the Cat II is the better (only) option.  But generally, if both are available, setting up for the Cat III is usually preferred unless some specific factor drives you to the Cat II.
Separate from this, some runways only have a Cat II approach and not a Cat III available.  This is typically driven by runway lighting differences, although other equipment may drive this as well (specifically, a backup Glideslope transmitter, IIRC).
As much as I hesitate to answer "always," I can't think of any Cat IIIA DA that's other than 50' RA, and I can't think of a reason it would be, since you're over the runway itself by that point.  Cat II DA's can be slightly above or below 100' RA since the terrain you're over when you reach 100' above the TDZ (on glideslope) may be slightly above or below the runway elevation, but that's a Cat II thing, not a Cat IIIA deal.

CATIII DH's can vary from 0-50 ft, with CATIIIA generally having a DH of 50 ft and CATIIIB having a DH below 50 ft (generally 0 ft/no DH). Some regulators prohibit approaches without DH, so you'll see CATIIIB-approaches with DH varying between 0-50 ft).

Other good reasons to choose CAT I -vs- II -vs- III are legal authorization to conduct the approach and aircraft equipment limitations.

From a historical standpoint, I find it interesting that "choosing" is now involved. In the "good old days" (not really, but it's convenient to remember only the good things) the question was simply whether or not we had the minimums for the equipment we had. The only thing that was going to change from a practical standpoint was the DH, and that was just a verbal call.

@Waked I was thinking of Cat IIIA, but you're quite correct that IIIB is a different set of considerations.

@Terry When you have a Cat III capable airplane & a Cat III runway, there is the choice of Cat I or II or III, with I being a bit less setup, and III having the lowest mins. Which opens up the question of why/when you'd want Cat II. Obviously, if you lack equipment or certification for Cat II or III, there isn't much of a choice to make there (other than, am I following or breaking the rules today, I suppose). But yes, in a jet capable of all of the above, there IS a choice to make.

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Do military pilots have flight & rest hours regulation?
I have read that civil pilots have stringent regulations regarding flight hours and hours of rest between flights.
What about military pilots? Does it change between wartime and peacetime? Between type of aircraft (transport vs combat)?

There's also hexedrine.

I'm pretty sure the whoever sends the out understands the dangers of fatigue and will rotate the shifts as needed (with perhaps some guidelines from higher up)

Yes, they do. My experience is with the U.S. Air Force, so my answer will be from that perspective, but other air arms have similar regulations.
USAF
From the 11-202V3, Chapter 9, Crew Rest, Fatigue Management and Flight Duty Limitations:
9.4.3 Augmented Aircrew

A basic aircrew supplemented by additional aircrew members to permit in-flight rest periods IAW paragraph 9.4.8. If the basic aircrew requires only one pilot and a second qualified pilot (includes pilots enrolled in an AETC formal aircrew
  training course) is designated an aircrew member to augment pilot duties, the crew can be considered augmented.

9.4.6 Flight Duty Period

FDP begins when an aircrew member reports for a mission, briefing, or other official duty and ends when engines are shut down at the end of the mission, mission leg, or a series of missions. FDP for UAS ends at final engine shut down, final in-flight handover briefing, or final crew swap, whichever occurs last.

Table 9.1 (Maximum Flight Duty Period in hours by aircraft type)

9.8 Crew Rest

Aircrew require at least 10 continuous hours of restful activities (including an
  opportunity for at least 8 hours of uninterrupted sleep) during the 12 hours immediately prior to the FDP. To ensure individual accountability and mission reliability, crewmembers should be officially notified prior to entering a crew rest period. A crew rest period cannot begin until after the completion of official duties.

So you can see from the chart that it depends on the type of aircraft, and the number of qualified pilots on board. But there are of course exceptions (e.g. the B-2 Spirit has been known to fly missions up to 44.3 hours), especially in wartime. All Air Force flights' risk is determined prior to the mission, and in training things like crew rest are instant no-flys, but when the needs of the mission dictate, pilots may have to overfly when they are the only or best option, or when exceptional circumstances dictate.
Also, from the Navy (I searched for other regulatory publications from other countries, but couldn't find any):
US Navy
From the OPNAVINST 3710.7T Chapter 8:
8.3.2.1.2 Flight Crew

Ground time between flight operations should be sufficient to allow flight crew to eat and obtain at least 8 hours of uninterrupted rest. Flight crew should not be scheduled for continuous alert and/or flight duty (required awake) in excess of 18 hours. If it becomes necessary to exceed the 18-hour rule, 15 hours of continuous off-duty time shall be provided.

8.3.2.2.a Flight Time

Daily flight time should not normally exceed three flights or 6-1/2 total hours flight time for flight personnel of single-piloted aircraft. Individual flight time for flight personnel of other aircraft should not normally exceed 12 hours. The limitations assume an average requirement of 4 hours ground time for briefing and debriefing

Do these apply at all times (i.e. are there exceptions when on high alert, special missions, etc.?)

@Lnafziger - yes, but you can apply for a waiver in circumstances like those and it would most likely be approved

@Lnafziger The 12 hour rule for mission time was exceded with some frequence on P-3 anti submarine patrols during the cold war/peacetime.  However, they had three pilots for 2 seats so they could get around that with a bit of a nap as pilots rotated.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
How long does flight planning take / when is it done / how is it done?
When I left an A320 today, the fuel truck was already there and refueling the aircraft. (At least, the hose was connected.) Also, a FA said they will fly back within 40 minutes.
This isn't much time, and I wonder if they start to refuel the aircraft before actually calculating the required amount. (Since it's a 4h flight, they'll need quite some fuel.)
So I'd like to know how much time is needed for flight planning of an airliner. Maybe some planning for the next flight can already be done in advance during the current flight? Maybe some part can already be done by others?  Or does the entire process take just a few minutes today?
It's also not clear to me what is done during flight planning. Of course planning the route, including possible ways to divert the aircraft, and amount of fuel. What else?
EDIT: To make it more clear: I'm asking about the work the pilots have to do to prepare for the next flight

Timelapse of turnaround operations --- Repetitive flight plans (RPL) are usual and there is a team in the airline for flight planning and dispatch.

This question is rather broad, however, I think Mike has probably nailed the gist of what the OP is after. Maybe some rewording along the lines of "how is flight planning handled to allow for an individual plane to have a 40-minute turnaround between gate arrival and push back", would help?

@mins - if only that time lapse indicated how much real time had passed...

The pilots don't do the flight planning. It is done 1-2 hours before the flight by dispatchers using computer software.
On a quick turnaround, one pilot goes to a printer to retrieve the flight plan. The other stays with the aircraft and prepares for the next flight.
Sometimes someone will bring the flight plan directly to the aircraft. Some airlines have stopped using paper flight plans and instead download to an iPad.
The pilots review the flight plan to ensure it meets all requirements, and can request a reroute, or additional fuel it they feel it is needed.

When is flight planning done?
Anytime convenient! Honestly. You can plan for a trip 3 hours later, tomorrow, next week, or even next month. There're already pre-defined airways on most areas you'll fly above; you just need to lookup the charts and select yourself a route.
Now, unlike a family road trip, commercial flights are flown everyday. Every pilot assigned to the flight will make that trip. So, no, pilots do not arrive at the gate, being told "Your next hop is going to Hawaii", then grab the charts, lay them out on a nice big table, and figure out which waypoints to go. Somebody at the company has already done that for them. That somebody is called a dispatcher.
And remember, it's the same route flown over and over again, day by day. You only have to plan once.
When do I know how much fuel to take?
To figure that out, you need to know how much cargo and how many passengers are going on this flight. When will you know that? A few hours before departure, you already have a good estimate (given that usually x% of passengers will turn up). By the time check-in for this flight is closed, you have the exact number. Just plug in that number into a calculator and you'll get your fuel requirement. Even without computers, this calculation takes only a minute.
Pilots' responsibility
The pilots (in particular the captain) has the final and unquestionable authority over any matter of the flight, including its flight plan. That said, pilots are not the ones who come up with the initial plan. In airline operations, the pilots' responsibility is to adjust the plan as necessary. For example, if bad weather is expected at the destination, the captain might request extra contingency fuel.
So in short, the pilots' responsibility include:

Familiar themselves with the planned route
Review the weather forecast and NOTAMs, and adjust the flight plan if necessary
Verify the weight and balance is appropriate (taking into consideration cargo, fuel and passengers. Again, somebody has already done the calculation for them.)

That's not much, indeed.

winds and other weather conditions affect fuel load significantly, so it's not true that you only have to plan once.

@pericynthion Yes and No. Jet streams are present all year along; its strength and location does vary, but within limits. Furthermore the software used by dispatchers can take winds aloft into account. So you only plot the route once. You figure out cruise speeds, cruise altitudes etc. a few hours before takeoff. Sometimes you have to re-route around volcano eruptions and hurricanes, but that's not often.

The first paragraph makes it sound like you can plan a flight a month after it happened...

@kevin, depending on where you are flying, you might also need to reroute around congestion, strikes and other disruptions. I don't know how often they happen, but I would think more often than volcanoes.

Well, a 40 minute turnaround time can be quite short to leave time for planning.
Mind you it's not just about choosing an appropriate flight route, but weather considerations, reading Notams, winds, choosing an appropriate flight level, deciding on extra fuel, choosing takeoff alternates, en-route alts, destinations alts, then the w/x and Notams for those alternates, etc.  It can probably be done in 30 minutes , but it will be hairy.
Normally all my sectors (legs?) are pre-planned/read/briefed at the beginning of a work day. Deciding on most important factors before we even go to the plane.  Then, when we have to do a 40' (30'?) turnaround it makes it all much easier. Most times we can call ground handling companies via VHF before we even land, informing them in advance of the services we need (including the amount of refuelling).
How long does flight planning take
Computers print an OFP in probably under 1 minute. Then maybe 5-10 minutes for the pilots to read/change/understand/brief.
when is it done
At the beginning of the work day
how is it done?
uhm.. see above
I'm asking about the work the pilots have to do to prepare for the next flight
Ok, different question as it is not so much planning related:

Refuel
walk-around check
prepare the FMC (in one way or another)
review the mass&balance loadsheet
compute takeoff speeds
review and brief the departure

and you are good to do. Did I forget anything?


text:
What do manufacturers do to reduce cabin noise?
It is being claimed by the Airbus that their new planes offer more sound proofing than those of Boeing, and I myself observed the same. How do airplane manufacturers tackle with the problem of soundproofing the cabin, so as to reduce the noise reaching inside from outside the plane (the engine sounds and the free stream noise)? What proportion of the total aircraft development cost would this be (approximately, say for an Airbus 320 and for Boeing 777)?

it is being claimed by the Airbus that their new planes offer more sound proofing than those of Boeing

I guess you mean this sort of claim:

No matter where they sit, all passengers benefit from the quiet A380 cabin with on average half the sound energy of other aircraft. Passengers' feedback confirms the extraordinary contribution to their general well-being due to the absence of background noise on the A380.
In market research surveys the A320 is regularly rated higher than its rivals for the low level of noise in its cabin. Effective insulation in the cabin is one reason why passengers say they find the A320 a quiet aircraft in which to fly. The A320 cabin is the subject of continuous improvements and in its latest version, the noise has been reduced by a further 1dB.

how do Airplane manufacturers tackle the problem of soundproofing the cabin

There are a variety of methods

soundproofing materials in the wall of the fuselage between inner and outer skins.
choice of interior materials and furnishings etc.
adjusting cabin interior contours to allow lower airflow velocity.
fuselage aerodynamics.
engine nacelle accoustic liners.
scalloped edges on engine exhaust nozzle.
larger slower engine fans.
sharklets.
etc

BBC report

One of the main sources of noise is wind. So during the design phase of modern aircraft, computational tools model the aerodynamics of the aeroplane to highlight areas of high airflow that are likely to increase cabin noise. This allows engineers to reshape their designs, says Alan Pardoe, director of product marketing at Airbus. Such techniques, he says, helped the double-decker Airbus A380 plane to be recognised by the UK Noise Abatement Society as the quietest jet airliner on the market.

Airbus say

When it comes to making the A380 one of the quietest aircraft in the sky, it's the small details that count... in fact, more than 3 million of them!
This is the number of tiny perforations in acoustic linings on the large nacelles that surround and protect the A380’s jet engines.  The acoustic material helps dampen noise created by the airliner’s four turbofan powerplants, ensuring the A380 is a friendly neighbour wherever it operates in the world.
  The A380’s nacelles are supplied by Aircelle, which has worked closely with Airbus in minimising the jetliner’s noise output during takeoff and landing.  Acoustic panels are applied throughout the engine – from the air inlet to the exhaust nozzle.
Each panel, which is produced from composite material or titanium, is designed to attenuate noise at different frequencies, further improving the soundproofing effect.  Noise-reducing innovations include Aircelle’s 2-degree-of-freedom acoustic panels, which use a stack of two honeycomb composite sandwich layers separated by a porous wall.
These panels dampen high-frequency noise from the engine turbines.  With much of this noise source successfully dampened by the acoustic treatment, engineers and designers are now focusing their attention on treating other sources of aircraft noise, promising even quieter jetliners for the future.

and also this

The Airbus-developed Zero-Splice engine nacelle liner was designed to reduce the noise generated by the jet engines’ large fan, which represents almost half the noise during both approach and take-off. Following extensive studies carried out by Airbus on how to reduce fan noise, it was found that splices used to join the engine nacelle inlet’s acoustic panels generated forward fan noise – which was counter-efficient to the liner’s acoustic treatment. Airbus therefore developed the Zero-Splice nacelle liner as a single 360 deg. piece of composite, which is comparable in size to the diameter of an A320 fuselage.

It is, I think, obvious that measures that reduce engine noise on the ground also reduce it in the cabin.
They also write about how wing sharklets reduce noise.
I'd guess there are many other measures and design choices that are introduced to reduce noise.

What proportion of the total aircraft development cost ...

I'd be surprised if Airbus or Boeing make public any breakdown of their development costs.
You can find general breakdowns like the following but I havent found any that break out soundproofing development costs.

Strictly for the DC-9/MD-80 series there are two methods available.
One is the engine sync system which synchronizes one engine to the other to prevent the droning sound when the engines aren't running at quite the same setting. There are two modes N1 and N2. The system compares the speeds of the two engines and adjust the left engine to match the right engine. When the system switch is turned OFF, the system continues to SYNC the engines using EPR.
The other is an active noise reduction system which adds new engine mounts designed to reduce the noise.
http://www.flightglobal.com/news/articles/lord-nvx-system-quietens-dc-9md-80-cabin-1554/

LORD HAS RECEIVED US certification for its NVX active noise-and-vibration control system on the McDonnell Douglas DC-9 and MD-80. The company says that its system is the first to be approved for use on large commercial aircraft, and "...is being considered for several DC-9/MD-80 installation programmes." Approval follows installation of the NVX on a corporate MD-87.
The system consists of actuators on the engine-mounting yoke which counteract engine vibration and so reduce cabin noise. The actuators are driven continuously by a controller based on cabin-noise data from microphones installed behind the trim or under the floor.
The results are most noticeable in the aft cabin, where engine tones typically measure 20dB above background noise, says Lord, adding: "The NVX Active System eliminates these tones on the ground, as well as during take-off, cruise and descent." Programme manager Becky Weih says that noise levels are so reduced that the rear of the cabin "...is no louder than the front". Erie, Pennsylvania-based Lord says the NVX has been approved on several corporate-aircraft types.


text:
Is there ATC audio from the Sled Driver Speed Check story?
I love this story, like a lot of people, but is it possible to find the actual ATC recording from that story?
Excerpt:

Then, I heard it. The click of the mic button from the back seat. That was the very moment that I knew Walter and I had become a crew. Very professionally, and with no emotion, Walter spoke: "Los Angeles Center, Aspen 20, can you give us a ground speed check?" There was no hesitation, and the replay came as if was an everyday request. "Aspen 20, I show you at one thousand eight hundred and forty-two knots, across the ground."
I think it was the forty-two knots that I liked the best, so accurate and proud was Center to deliver that information without hesitation, and you just knew he was smiling. But the precise point at which I knew that Walt and I were going to be really good friends for a long time was when he keyed the mic once again to say, in his most fighter-pilot-like voice: "Ah, Center, much thanks, we're showing closer to nineteen hundred on the money."

This would probably be pretty difficult to locate. The story doesn't give a date but I'm guessing its in the 70's. ATC audio would have been recorded on mag tape systems and frequently reused/overwritten if even recorded at all. Unfortunately the best account you are going to get of this is what you've read from the book.

Related: How did planes measure their speed relative to the ground before GPS?. Not sure this story is true, or some pilots are such children...

1,842 knots over the ground.... Closer to 1,900.  Great story.

@mins...some pilots are such children.

Sadly, there likely are no official recordings of this story.
Unfortunately, there was no LiveATC.net archive at the time, and unless there is an accident or incident, audio is not routinely archived by the FAA or NTSB.
Even when you want to request recent data, the FAA warns, "Because air traffic data is routinely destroyed or disposed of in the normal course of business, time is of the essence." (I've seen elsewhere but couldn't find an official source that it can be anywhere from 5-45 days), so even if you could find a date of this event, you wouldn't be able to file a FOI request.


text:
Can the FAA CPL 2-hour cross country flight requirement include stops?
One of the requirements for an FAA commercial certificate is:

§61.129: (3) 20 hours of training on the areas of operation listed in §61.127(b)(1) of this part that includes at least—
...
(iii) One 2-hour cross country flight in a single engine airplane in daytime conditions that consists of a total straight-line distance of more than 100 nautical miles from the original point of departure;

Since it just says 100 nautical miles from the original point of departure, would a flight that was 268 NM and 2h 29m, but included a stop halfway count for this requirement?
Also, does the "20 hours of training" mean that the 2-hour/100 NM flight needs to be with an instructor?

is it just me or is "nm" nanometers while "NM" is nautical miles?

@FreeMan updated, but I think it was pretty clear in context.

Sorry, that was really just me thinking out loud as a non-pilot and being momentarily confused by your title.

The general rule of reading the FARs is “Don’t make them more complicated than they are.” If you are in the air more than 2 hours and land at a point more than 100 nm away, then you have satisfied the requirement. I used my flight to get night current and landed at 2 airports along the way.

@ymb1 In his case, yes. In my case, the destination was 131 nm away and in a  C210 is less than an hour. So the round-trip time would be less than 2 hours. Adding the stops along the way extended the total flying time to more than 2 hours.

Everything in §61.129 Part 3 falls under the training wording so an instructor is required. They should explicitly log it as training required by §61.129 in your log book.

Affirmative.  That flight will have to be part of the dual training time required for the airman certificate.
And, yes, you can do a stopover during the flight; the experience requirement does not prohibit it.


text:
How quickly can someone learn to fly?
I'm a US-citizen living in Japan, and the costs here are insane ($500 per hour). So I'm thinking to go to the US or Australia for my pilot's license, but how long am I'm going to need to live there? Could it be done in 2-3 months? Less?
This question discusses the cost of learning to fly, and it's mentioned that people often take a year (flying once a week) to see the hours. My question is: reasonably speaking, how quickly can someone get their license?  I'm not actually looking to go from "zero to hero" in record time, I do want to learn the material and enjoy the process. But wanted to have a rough idea of the lower limit so I can plan for the total costs (housing, time away from work).
If you need 40-50 hours of flight time, and you fly 2-3 times a week, what is the typical duration of these instructional flights?  How many hours can someone realistically book in a week (I hear flights get cancelled)?
In reply to the comment about individual ability… I have a high-IQ and have taught myself many things throughout my life. I'm a software engineer with 20+ years experience (created my first commercial software application around age 12), I've authored several top-selling Japanese language books, I taught myself photography and have two Page-One credits in the NYTimes, I learned freediving and 9 months later I won an event in a competition in Japan and ranked 11th nationally, etc. When I put my mind to something I'm focused and disciplined. How much does it really depend on my ability and how much depends on class hours and flight time?

I can't say anything about how good of a program it is, but this place claims it can get you a Private Pilot's License in just three weeks.

This is a subjective question. How quickly one can learn a skill depends more on that individual than the skill. I doubt there is any restriction by law. That being said, my doctor (for class III medical) who is a pilot too, told me that he did the entire training in just 3 weeks.

FWIW, I got mine in one month but that was in South Africa and the US training includes a few extra things that SA doesn't (or didn't). But since that included time off for myself and for weather, I'm fairly sure you could do it in one month provided you have a) the right weather (Arizona?) and b) the aptitude. And c) the money :-) You might also want to think ahead to how you can keep your license current in Japan, if it's so expensive (unless getting it is just a bucket list thing).

@raptortech97 It appears (from the picture on their homepage) that they'll teach you to fly but won't advise how not to trip from the landing gear. :)

Also, check out AOPA Japan and this Pilots of America thread; converting a PPL to the Japanese equivalent is not trivial.

Hi all, it's more of a 'bucket list' thing--not important to transfer license to Japan. I'd just like to have the experience--ideally flying diverse types of planes. (I dream of flying a P-51!) I saved up plenty of money, and thought it would be a worthwhile experience for $10-20K @Farhan edited question to address intelligence level.

If the ability feedback was directed at my comment about "aptitude", I guess I should say that IMHO if you can drive, you can fly, and I'm not doubting your personal abilities. Perhaps I should have said "determination". But, many people do drop out for different reasons, and I've also observed that different people can get hung up on different tasks and need some time to get over the hump: in my case it was landings, in a friend's case it was talking to ATC etc. So there is a personal element. This may be easier to discuss in chat

@Farhan before you also raise issue of individual ability. So did my best to try and quality that, but point taken. Sure there are unknown issues. I might get terribly airsick the whole time ;)

@raptortech97 if you'd like to post your comment as a question I'm happy to accept. Seems like it's probably unreasonable to do it faster than 3 weeks.

I wasn't doubting your intellectual abilities at all. I was pointing out to the huge amount to prerequisite knowledge required to learn flying. Cessna syllabus is so detailed that going through it completely would take more than a month. But if you've studied it all and learn some maneuvers in a simulator, actual flying may not even take 3 weeks. And as @Pondlife pointed out, different people may need different times on a similar task.

finally, I'm not actually looking to skip over the material in record time. I want to learn and enjoy the process. But just wanted a better idea of the lower limit, so I can plan my costs (housing, time away from work). Will probably plan for about two months, and will self-study before starting. Cheers!

If you decide to come to the US, where you learn is going to affect how quickly you get a VFR ticket. And when you want to move up to an IFR rating, you actually hope for bad weather. Where you learn will also impact the cost (some parts of the country are much cheaper than others) A small school will probably be faster and more customized than a college program, if you're considering those...

Do the theoretical stuff beforehand. Come prepared and select a flight school with lots of time for you. I went to one in a remote part of Georgia and had two instructors to choose from and was their only student for much of the time (less than 2 weeks, admittedly). I could fly practically all day with a C150, a C172, a Beech Baron and a Katana. A colleague who went to a big school in Florida had to wait in a queue all day to get a handful of brief flights.

The absolute minimum would be about 45 hours. The FAA requires 40 hours of flight time, the completion of an aeronautical knowledge course, a written test, and a flight test. This assumes that you can read and memorize all the necessary aeronautical knowledge in an hour and a half.
In the realm of humans who like to eat and sleep and actually learn and such, you might be able to do it a little faster than 21 days. This flight school offers an accelerated PPL program that they list as taking 21 days, and they say that "[a]ny of these courses can be completed in less time than what is listed above, however the courses are based on the average time to completion." Of course, if there's a lot of inclement weather, that could slow things down.

Back in the 1960s (yes, I know, that's prehistoric), under the FAA's approved school program of the time (Part 41?), you could get a private in 35 hours and a commercial in 160 hours. Does that still apply? And just to make everyone feel good in these days of high cost, my total expenses including the fancy sunglasses were $679.95 to get my private.

@Terry Yes, a part 141 school can get you a PPL with 35 hours flight time and a commercial with 190, but you must take their ground schooling, which has a strict, specified curriculum, so it ends up taking longer (at least for the PPL).

Accelerated might not produce the best result. The time between lessons can be valuable "settling"/"integration" time for new knowledge and experiences. I once came upon a claim that for flight instruction, 2-3 lessons per week was an optimal pace - slower and previous lessons may not "stick", requiring further repetition; faster and it may go by too quickly to all be absorbed - again requiring further repetition.

@Terry: that would be around or over 5000 of todays dollars.

@PlasmaHH That's still good, by today's prices.

Took me a while but that's because I started when I was 14.  I got my pilot's license before I got my driver's license.  "Back then" (late 80's) it cost me about $5K.  But then I had more training than I needed to take the pilot's test...had to wait until I turned 17!

I did it in 17 days - start to finish.
Did flight school in Arizona.  Before I went, I got the PPL study guide, MS Flight Simulator complete with a yoke, pedals, and throttle quadrant... and put in dozens of hours just learning the instrument scan and practicing virtual stuff.
When I got to the flight school, I already knew the parts of the plane, and what each control did.  I knew about maps and plotting courses.  I understood the physics of flight.  I knew about VORs, VASIs, NDBs... I knew about stalls and corrective procedures - from an academic standpoint.
As such, my under-the-hood training was by-the-numbers.  My seat of the pants stuff was only hampered the first few days by the awful flying conditions of AZ in July heat.
That said, I aced the written, and did my 3 required solos in two days.  I went to a flight school run by a Gold Seal licensed FAA examiner so I didn't have to depend on the FAA to squeeze me in.  And I passed.  17 days.
ONLY flew tricycle gear stuff.  No taildraggers.
Other than the serious prep beforehand, there were three main drivers for my success:

I flew at LEAST once a day - many times twice.
I wanted this more than anything I had ever wanted before.
I only had enough money and vacation accrued to be there for 3 weeks total - no more.

Best of luck!

Welcome to [aviation.se]! Awesome first write up and description. Hopefully you'll register your account and stick around.

How much did this cost you total, @Mike, if I may ask.

CGCampbell - thanks!
RoboKaren - funny thing...  I live in CT.  I priced it out here and found it was LESS to fly to AZ, spend 3 weeks in a motel, AND learn to fly out there.  The place I went had free ground school - so that's where I spent my evenings and afternoons.  Most flying was VERY early morning or late afternoon.  (I soloed at 6:20 AM)  Any other time was just oppressively hot and the density altitude made it hard to get off the runway without a climb prop.
This was back in 1998... so I don't recall exactly what I spent... I'm going to guess I dropped maybe $7K?

I think the plane was ~$85.00/hr wet.... free ground school.  Stayed in a clean but nondescript motel in Tucson.  Ate a lot of fast food.  Did ONE site seeing thing over a weekend, but otherwise - full-tilt flight school.  Sadly, I think Snoopy's is out of business now.  My FI was a British guy named Tim (can't remember his last name - but it's in my log book. :)  )  Denny Genzman was the gold seal instructor who also owned Snoopy's.  And yes - the flight school pre-dated the cartoon.

I go once or twice a week if the weather holds and I'm up to almost 8 months (and I am still not done (PPL)).
I work with a guy who religiously went 3 days a week and said he got it done (at a part 61 school) in 6 months (almost exactly).
The limiting factors are of course money (which does not sound like you are worried about if you are planning an endeavor like this). And of course weather (which you can mitigate by going to a place in the country that has better year round weather like the south west), if you come during the summer and get 3 solid months of clear days and potentially never have a flight canceled you will be good. I have had 3 flights canceled in the past 3 weeks due to high wind or rain.
As for booking you can book as many hours as your instructor/aircraft will allow. Some instructors are part time which can limit how much you can book, and some schools have only a few planes but generally allow you to book way in advance so if you have the plane and instructor you can book every hour of daylight if you like. Keep in mind that trainer planes have 100 hour inspections and will be out for maintenance when another student inevitably has a prop strike...
As for ability that depends on a lot of things. You will most likely get the maneuvers down fast and then it will be all landing work. If you get those down fast (and they say the more frequently you fly the better it is) you can be done quickly.
You can mitigate some of this by self teaching yourself the ground material, although some schools (if not all) will require you to sit for a certain amount of ground lesson hours.
Edit
The amount of hours you get in a single day will depend on what you are doing and how long you can be up for. The way I was taught there was usually some pre flight instruction (outlining what we were going to do). Then I had to preflight the plane. Then get in, taxi out (I was at KPNE, so there was a solid amount of taxi traffic to contend with on occasion) go practice maneuvers or stay in the pattern and practice landings then some post flight discussion. All told for an hour and a half on the Hobbs I would some times be at the airport for 4 hours or more. I would think that realistically (assuming you need to eat lunch in the middle) and discuss things on the ground etc, you could get maybe 5 hours of actual flight time in, in a day. This will also depend on the season since the days are significantly shorter in the winter. Up hear in the north east there is a solid extra 2 hours of day VFR time in the summer.
Edit 2
You could on some level use a sim before you went about this to familiarize yourself with the aircraft instruments, how they work, and what certain control inputs will result in. A decent setup using X-Plane will only cost you a few hundred (USD) and be a lot of fun in its own right. The issue you will hit is that to much sim flying can result in BAD habit development. Sims are a great learning tool but don't always feel like the real thing so as long as you use it as a learning tool you will be fine. Some sim's even allow for simulated ATC communication which can really help you hone in your radio skills (something that will be overwhelming at first.
Edit 3
I see in the comments that you wish to one day fly a P-51. Assuming you are talking about doing so solo its worth nothing that the P-51 is a "Tail Dragger" also known as conventional landing gear. Most modern trainers have tricycle landing gear so you will have to get checked out in a conventional gear plane. You will also need a high performance rating to fly a plane with that much power as well as complex for the folding landing gear. While we are on the topic you mention flying lots of different types of planes this is not as simple as you would think. Most places will require type specific time (time in that particular model of aircraft or a very similar one) before letting you fly/rent it. To fly in lots of different aircraft right after having you license you will be spending lots of time with instructors in the plane as apposed to solo time.

Thanks Dave! Another excellent answer on sim software strengths and weaknesses can be found here http://aviation.stackexchange.com/a/1051/8201

Yes, at least in the US it is completely reasonable to do it in 2-3 months. I believe you can achieve this easily in a month's time if you're doing it full time.
The following applies to the US,  where I'm most familiar with the rules.
The process in the US as an alien is as follows:

Find a flight school and notify them that you'd like to begin flight training
Receive authorization from the TSA to begin flight training
Get a Medical Exam
Fly 40 hours (more on exact requirement below)
Receive an endorsement to take the written knowledge test
Take the Written Knowledge Test
Receive an endorsement to take the practical test
Take the practical test

The 40 flight hours have some additional requirements:

20 hours with an instructor

3 hours cross country (where the flight leg is at least 50 nautical miles)
3 hours of night flying

1 cross-country flight of at least 100 nautical miles
10 take offs and landings to a full stop

3 hours of instrument flying (you wear a view-limiting device like this one)
3 hours of flying within 60 days of the practical exam

10 hours of solo flying

5 hours of cross-countries
1 cross-country flight of at least 150 nautical miles with landings at 3 different airports
3 take offs and landings at an airport with a controlled tower

Here are some tips to accelerate the process:
While you're still in Japan:

Identify a flight school that is familiar with accelerated flight training, for example Double Eagle Aviation or Tailwheels Etc.. You should go to a place with good weather and choose a time of the year to maximize flying days (e.g. sunny, little wind, cool days or low altitude). Call and notify them that you'd like to begin flight training (check availability, schedule the course).
Get the endorsement for the FAA Written Knowledge Exam. You can do this through an online ground school course, like Sportys or King Schools. There are various others you can find online, just make sure they will provide you with an endorsement for the FAA written exam.
Become familiar with the TSA's Alien Flight Student Program and review timelines, process, and requirements. You will need to be fingerprinted at specific locations and the process can take a week or two.

Then, as soon as you land in the USA, get fingerprinted for the AFSP and while you're waiting for authorization, get your medical exam and take the written knowledge test.
I hope this helps!!!!

A few comments:
The older you are the longer it takes. A generalisation yes, but I've been teaching people to fly for a few years and like it or not the spotty teenager wins every time over the old and wise!
Flights of more than about an hour or an hour-and-a-half become counter-productive. Lots of short flights are far better than long sessions. Your mind stops absorbing stuff as effectively after the first hour. If you have 2 or 3 hours booked then land, have a coffee, debrief ( even to yourself ) the past hour and start again. Apart from Navigation exercises a 3 hour flight is just a jolly for the instructor.
Fly with a purpose. decide what you want to do in each session, be honest and practice the bits you are not good at.
If you cram a licence understand that the learning curve after you get the ticket remains high. You learn more in the first 100 PIC hours than you ever thought possible!

Regarding possibility to do it in 2-3 months time, yes a PPL is quite possible, but a Ground study before even the course starts will allow a much better experience.
I'm an aerospace engineer, and had flown flight simulators a lot, before joining the PPL course. In my experience, ground instructions were more about chatting with the instructor on ideas, techniques, and general information and experience. These side-notes are important and not all can be found on the books.
For a tentative schedule of 2-3 flights per week;

until the solo flight, the flight times would be 1 or two hours each. Solo flight could be around the 10th hour, depending partly on your body skills and partly on knowledge of rules and procedures, so it would possibly take two weeks to fly solo.
And then it could be 2-3 hours or longer flight each, where you practice more on landings, navigation, emergencies, and weather. Before and after each flight is the time where you enjoy as much as the flight itself, thanks to the fellow students and other instructors. You could assume that this would take 3 hours on average and if you have 40 hours, you would need 13 flights, which could practically occur in 5-6 weeks.

Assuming all goes well, 2 + 6 weeks = 8 weeks seems to be the normal paced course for flight. Ground courses take some serious extra time but depends more on personal literacy and capability to pass the tests, and could even be handled beforehand.
I attended the PPL course in Ankara, and the theme was just great.

As far as searching for a school, use on line resources such as the AOPA, that's the Aircraft Owners and Pilots Association, and search for instructors. The school is one thing, but the instructors can sap your money and time without moving you forward. About the only place you can count on for weather is California. Now you have very high fuel prices as compared to the rest of the country which translates into high hourly rates for the plane.
If you have the resources buy a Cessna 172 and use that for training. Many schools charge a nominal fee for the instructor (\$50/hour at Easterwood Airport in College Station, Texas) when you use your own airplane.
You can purchase a C172 for less than $40000. The cost per hour goes way down. When you get your license sell your plane and move to whatever you want. If you get one that is IFR certified you can use it for your IFR rating after you get your PPL. Some schools will lease your airplane for training others. There are many instructors NOT associated with schools which you may be able to work out a deal with.
Check into Flying clubs. The Bay Area Aero Club in Pearland has great rates on airplanes. They also have a long list of "Approved" instructors which you contract with privately. There are hundreds of flying clubs like it in the US. You can also search for clubs on AOPA.
Three months is not out of the question. There are flying schools advertising in the Flying magazine all the time which guarantee passing the written test within a week. Time and money. That's all it takes.
You should be able to solo within 10 hours of flight time. If you have a good instructor you will be more than ready. The cost of the Practical Exam by a FAA Approved Examiner can be between \$400 and \$500. The practical Exam can be taken free at an FAA field office. There are very few of those. If memory serves there are seven regional offices. That's why they have approved examiners. My examiner cost me $500.
Good luck. Happy flying!

In Argentina we have a 40 hs minimum to take the exam. As I learned in one of the busiest airports near Buenos Aires, it took me a little more -56 hs- because it included much radio communication and control procedures that other flight schools in other cities don't need.
As many other pilots, the experience with MS Flight Simulator really helped.
Looking back, I feel you can learn to fly in the first two hours or so. Then you happily spent your money learning how to land in one piece and walking... Don't limit yourself, take your time and be safe!


text:
Why don't big airliners have bigger doors?
Reading this question I saw this picture in MikeFoxtrot's answer and noticed how easier it would be to board the plane using that huge door:

I understand that for single aisle planes you wold need to form a single line anyway, but for two aisle planes having a wide door could speed up the boarding process a lot.
So, is there a reason why it is not done? What is the limiting factor in the door size?

Note, too, that there is the large cargo door, used for loading the seats, and the smaller passenger door right in front of it, used for loading the seats' cargo. Imagine walking up a set of stairs to the gaping hole in the side of the plane, only to be confronted by 4 rows of chairs - you think getting on a plane takes a long time now!

Great, a bigger door to wait in while people cram their luggage into the overhead bins and squeeze into the economy seats.

Regarding the logistical reasons for not using larger doors.

I think you will find that the bottleneck in the boarding process is not the door, but further down the aisle about row 14 where a small person is attempting to earn an Olympic Medal for his/her weight class by stuffing all his/her worldly possessions into the overhead storage compartment.

Or 2 people arguing endlessly with everyone else about wanting to sit together in seats that are completely different from the ones assigned to them, until a flight attendant manages to push herself 25 rows aft and negotiates a solution ten minutes later.

Multi-aisle commercial aircraft adopt a multi-door boarding strategy rather than a single-huge door (see the A380 or the B747, both use two doors). This helps under the structural viewpoint: the presence of a door (cargo or passenger that might be) induces design problems that are amplified if the compartment has to be pressurised.
A door interrupts both frames and stringers and weakens the overall aircraft structure. A huge door interrupts many more frames than a small one and two small ones can be set apart from each other to have some continuous frames between the two, restoring some rigidity.
The complex closure systems ensure that part of the stresses are carried by the door material, but it will never be perfectly transmitted as it would be without a door. As mentioned before, the stresses are heightened if the compartment is pressurised (as when passengers have to be transported).

A small comment here: A380 can use upto 3 doors if airport is equipped.

Actually, the aircraft doesn't even have to be multi-aisle to use two boarding doors. Some airports/airlines do that with 757s, for example. All you need to do this is an aircraft with at least 2 doors in front of the wing, though that does generally exclude most aircraft smaller than the 757. In the case of single-aisle planes boarding with 2 doors, the first door is usually used for boarding first class and the other used for boarding economy.

also, some airlines at some airports in the states use a front and back door. Some 737s (Southwest, if I recall) are loaded from both front and back at SJC and BUR.

@vasin1987 Why only 3 doors? Doesn't A380 have like 8 doors?

@Firee three doors are used for normal passenger loading/unloading. The other thirteen doors are used by passengers only in emergency. Normally they are used to service galley, loading food carts etc.

Before answering your question, please take a look at the excellent answer to Why aren't planes loaded from both ends?, which talks about increasing efficiency in boarding passengers.
Airliners do not need bigger doors for boarding people because people are not like big crates which are loaded into airplanes using forklifts.
To incorporate a wider door, we need to do the following:

have a bigger foyer inside the door
All space on a passenger airplane is fully utilized to the maximum extent. Having a large area just to greet passengers and help them to their seats is not a very efficient use of that space.
size of jet bridge
New jet bridges will be needed, which can allow more than two people walk side-by-side.
gate procedures
Most of the airlines have designated their seats into zones1. When boarding, people are called in a manner which expedites the boarding process. With a bigger door, this process needs to be adjusted for boarding more people at the same time.

At present, only A380 has an upper deck for passengers, which extends the length of the aircraft. They already have multiple jet bridges to maximize the boarding process:

Image Source

1: Not talking about travel classes.

Why not just have it open into the bar/lounge/lobby?

@fooot The bar/lounge/lobby isn't on every A380, and not on both levels. I think it might not of on all A380s of a specific airline either.

I'm actually not certain that the boarding zones really have anything to do with your seat location on the aircraft. At least on Delta (the only airline I commonly fly that has boarding zones,) these are mostly just assigned by your status with the airline and/or when you checked in. It seems to be more for allowing frequent fliers or those who have paid for better seats or priority boarding to have first access to the overhead bins and managing the flood of people rushing the gate at the beginning of boarding than for actually loading the plane efficiently.

"...because people are not like big crates which are loaded into airplanes using forklifts."  What if you had the passengers board the seats outside the aircraft, and then forklifted the blocks of seats in?

A door involves reinforcement of the structure around it (on the fuselage), so a bigger door involves more structural reinforcement, which means it adds more weight (because of the beefier structural reinforcement). In airplane, whatever you do, you want to keep the weight of the structure as low as possible, so you can carry more people. It's economic reason (the airline is a business). Technically windows need structural reinforcement as well, but without window it would be boring, and probably less people would fly (they would feel less safe to not see outside).
The cabin is pressurized, so the bigger the door, the more pressure pushing to pop it open (which is why it would need beefier structural reinforcement)

Airliner doors generally open inward. Pressure from the inside won't pop them open, at least not without ah... major structural failures.


text:
What is needed to certify an aerodrome as an airport in Canada?
So here.
All airports are aerodromes. All aerodromes are not airports.
Difference between Airport and Aerodrome:

An aerodrome or airdrome is any place from where flight operations can take place. This can include an airstrip in the middle of nowhere to a commercial airport in the biggest city in the world. An airport is a special type of aerodrome that has satisfied certain certification criteria or regulatory requirements of the ICAO that a regular aerodrome may not have achieved.
The term airport implies a certain stature of having satisfied certain certification criteria or regulatory requirements of the ICAO that a regular aerodrome may not have achieved. Hence it can be said that all airports are aerodromes, but not all aerodromes are airports.

So then what facilities and services does an aerodrome need to have, in order to be certified as an airport in Canada?

Short answer

An operator of a certified airport is required to conduct airport operations according to an Airport Operations Manual.
This manual must enumerate the facilities offered by the airport.
An important aspect of the manual is to describe how airport safety and emergencies are managed, and by whom. Note that the obligations for safety are not specific to airports, but apply to any aerodrome. what is required for an airport is to write in the AOM how they are implemented.

So the difference between an aerodrome and an airport is not about the facilities or the equipment, it's about how it is operated and who checks it is done as intended.
Indeed some equipments are required at an airport (e.g. markings, lights and signs) but they are not specific to airports, they apply to all aerodromes.
Layman language

Aerodrome usually refers to the possibility for aircrafts to land and take-off. This is the point of view of a pilot with needs to takeoff and land. The word aerodrome is derived from the Greek words aeras (αέρας), "air" and dromos (δρόμος), "road" or "course", literally meaning "air course" (Wikipedia).
Airport usually refers to an aerodrome with passengers or freight facilities. This is the angle of view of an airline conducting business. In Canada there are obligations associated with running an airport.
International airport usually refers to an airport with customs and immigration services.

Aeronautical language
For the aeronautical information, a Canadian airport remains an aerodrome. E.g. a list of aerodromes.
Canadian authorities language
In Canada, an airline making business with air transportation must operate at aerodromes holding an airport certificate, aerodromes referred to by the Canadian authorities as airports.
From Canadian Aviation Regulations “airport” means:

an aerodrome in respect of which an airport certificate issued under
  Subpart 2 of Part III is in force.

Issuance of the certificate is described at section 302.03, and obligations for the airport operator are described at section 302.07. This is a very long list of obligations. An Airport Operations Manual is required, and described at section 302.08.
Summary of section 302.07 - The operator of an airport shall...

Comply with the standards set out in the aerodrome standards and recommended practices publications
Inspect the airport [...] after any aviation occurrence...
Assign duties on the movement area and any other area [...] only to employees who have successfully completed a safety-related initial
  training course on human and organizational factors.

Summary of section 302.08 - The Airport Operations Manual must contain...

... all the informations necessary for the authorities to verify that
  the airport meets the applicable standards...

Physical characteristics
Obstacle limitation surfaces
Declared distances
Lighting, markers, markings, signs
Access to the movement area and control procedures...
Enumeration of the facilities and services provided [...] including air traffic services and aeronautical information and communication
  services, navigation aids, and aviation weather services
Emergency response measures
Airport safety measures
Safety management system required under section 107.02
Description of the safety management system's components specified in section 302.502

The operator of an airport shall operate the airport in accordance
  with the Airport Operations Manual.

ICAO publishes a set of standards and recommended practices (SARPs), including Annex 14 — Aerodromes, Volume I — Aerodrome Design and Operations. Standards are fully enforced by ICAO members, recommended practices are encouraged but still optional for members.

Summary

In Canada, airlines are required to conduct business according to specific rules regarding aircrafts, passengers, security, etc. One of these obligations is to use airports holding a valid certificate.
Airport operators are required to conduct operations according to the practices listed in related publications. They must use an Airport Operations Manual describing how these practices are implemented. The authorities deliver the airport certificate based on this manual, and on-site inspection.

Airports operators are required to install equipments such markings, but this is valid for any aerodrome.
Airport operators are not required to offer such services as immigration, ATC, weather station, refueling, gateways, etc, however they are required to publish, in the Airport Operations Manual, which services are available.

It's up to airlines to select and use the appropriate airports, according to their needs and legal obligations.

Wow. That is a really good answer... I'm tied between two now!

Original Answer
Aerodrome
It is an area where:

aircraft land
aircraft take off

Runway may not be present (in case of a water aerodrome).
Airport1
By definition2, an airport is an aerodrome with facilities for commercial aviation flights to take off and land
It is an aerodrome which has:

facilities to store and maintain aircraft
at least one designated operational landing/takeoff area (runway or helipad)
hangars
terminals
fixed base operators
airport aprons
air traffic control centers
passenger facilities (restaurants and lounges etc.)
emergency services
customs3
immigration3

Edit
I noticed that the question is updated to be only for Canada. In that case, airport requires the following:

have a safety management system in place
comply with airport safety standards and security requirements

Further reading
Aerodrome
Airport
Airport Design and Engineering Standards (by FAA)
Aerodrome Standards (PDF by ICAO)

1: Not all airports must have all of these to qualify as an airport.
2: I could not find specific regulations which define an airport.
3: In case of an international airport

So which are the facilities aerodrome must have to qualify as airport?

@JanHudec I could not find a definite definition, but I updated the answer.


text:
Why do some airports not have ICAO codes?
This is a follow up to my previous question What do numbers signify in airport codes?
In that case, I was asking why my local airport (Markham Airport) had a number in its code (CNU8). I later learned that the code was not really a code, but a Transport Canada Identifier.
This leads me to my question, Why do some airports not have ICAO codes? At my local airport, there is plenty of glider activity, and a flight school is also located there.
My main thoughts for the airport not having a code comes from the lack of an Air Traffic Control Tower. When declaring a landing, pilots have to do declare it on Traffic, which doesn't have a controller. It looks something like this (based on memory, I'm not a pilot but I hope to be one):

Markham Traffic, Aircraft Papa Lima landing on the grass strip beside whatever runway

Am I correct in assuming that airports without ICAO codes don't have codes because of the lack of a control tower? Or is there other reasons for this?

Wish I could find a reference for this question. I suspect it has to do with traffic volume. With the FAA, they generally seem to start an airport with a 4 digit code(state abbr, and 2 numbers, aka 20GA in some combo), then if it's busier they'd upgrade to a 3 character code(6A2), then if it increases then they'd bump to a 3 letter identifier(PUJ). Once it's to the 3 letter one, it's generally assumed to be ICAO compliant by adding a K in front for the Continental US. Now is this correct? Not sure, but that's the standard I've seen in upgrading identifiers in the US.

The reason why not all airports do is that there aren't that many ICAO codes, and there are lots of airports.

In the US there is a minimum level of weather reporting capability (among other things) required to get an ICAO identifier.

@cpast if what you say is the case looks to me that ICAO procedures are really obsolete or not needed.

The airport has to apply for an ICAO code. At a very local grass strip with a lot of glider traffic you might not have any use for the worldwide ICAO code.

Lots of airports without a control tower have icoa identifiers so it’s not related to that.

There is plenty of information on the Internet on how certain and specific identifiers came to life, however the codes are sometimes not directly assigned by ICAO, but by the member nations.

ICAO Document 7910 - Location Identifiers contains codes allocated by national governments, on behalf of ICAO, to airports, airfields and other facilities such as ATC and weather stations.

Ultimately, it is the national CAA's or other authorities' decision whether to assign a code and get it validated through ICAO. The decision may be based on political, historical or other reasons, there is no minimum requirements for airports to receive an ICAO code.

Am I correct in assuming that airports without ICAO codes don't have codes because of the lack of a control tower? Or is there other reasons for this?

The availability of a control tower is not a requirement for ICAO codes, even small uncontrolled fields with grass strips can have an ICAO code, example: EDKW / Werdohl-Küntrop (600m grass / uncontrolled / PPR)

One reason in the US to have an ICAO identifier is weather reporting. Sometime back in the 1990's the FAA changed a bunch of airports identifiers to ICAO standard identifiers as part of a change where they changed weather reports to ICAO standards. Non-ICAO airport identifiers don't work in the ICAO-compliant weather system.

I don't think that's correct, @Gerry. There are plenty of airports in the US which have weather reporting but do not have ICAO codes. A quick browse of Skyvector will show them: 1R8, 2J9, 24J, 28J, X60, etc, etc....

@randomhead At the time, that was the reason given for changing airport identifiers to ICAO format. Destin was 79J and changed to KDTS at that time. Since then, with automation they have greatly expanded the number of airports with weather stations. Do to the numbers, they apparently had issues with the renaming and just decided to affix the "K" prefix to the beginning of the old identifiers to make them work within the weather system. If you look at your examples, Bay Minette is 1R8 but if you hover over the weather station icon, it displays "WEATHER STATION K1R8 BAY MINETTE"

@Gerry: Correct, but I want to clarify an important point. Destin was not changed from 79J (FAA Location ID) to KDTS (ICAO). It was changed from 79J (FAA LID) to DTS (FAA LID), and the fact that the new FAA LID consisted of only letters allowed easy assignment of the ICAO identifier KDTS. Then of course we have the Weather Station identifier which is the FAA LID prefixed with K... sometimes that lines up with the ICAO identifier and sometimes it doesn't because there is no ICAO identifier.